A PIC And A Few Passives Support Breakout In Glorious NTSC Color

March 29, 2019 by Dan Maloney 27 Comments

“Never Twice the Same Color” may be an apt pejorative, but supporting analog color TV in the 1950s without abandoning a huge installed base of black-and-white receivers was not an option, and at the end of the day the National Television ~~Standards~~ System Committee did an admirable job working within the constraints they were given.

As a result of the compromises needed, NTSC analog signals are not the easiest to work with, especially when you’re trying to generate them with a microcontroller. This PIC-based breakout-style game manages to accomplish it handily, though, and with a minimal complement of external components. [Jacques] undertook this build as an homage to both the classic Breakout arcade game and the color standard that would drive the home version of the game. In addition to the PIC12F1572 and a crystal oscillator, there are only a few components needed to generate the chroma and luminance signals as well as horizontal and vertical sync. The game itself is fairly true to the original, although a bit twitchy and unforgiving judging by the gameplay video below. [Jacques] has put all the code and schematics up on GitHub for those who wish to revive the analog glory days.

Think NTSC is weird compared to PAL? You’re right, and it’s even weirder than you might know. [Matt] at Stand Up Maths talked about it a while back, and it turns out that a framerate of 29.97 fps actually makes sense when you think it through.

Continue reading “A PIC And A Few Passives Support Breakout In Glorious NTSC Color” →

Color Sensor Demystified

January 23, 2019 by Al Williams 13 Comments

When [millerman4487] bought a TCS230-based color sensor, he was expecting a bit more documentation. Since he didn’t get it, he did a little research and some experimentation and wrote it up to help the rest of us.

The TCS3200 uses an 8×8 array of photodiodes. The 64 diodes come in four groups of 16. One group has a blue filter, one has green and the other has a red filter. The final set of diodes has no filter at all. You can select which group of diodes is active at any given time.

Continue reading “Color Sensor Demystified” →

Arcade Asteroids, Now In Colour

October 13, 2018 by Lewin Day 11 Comments

Asteroids is one of the classic games of the early arcade era. Launched in 1979 by Atari, it relied upon using an XY vector monitor to deliver crisp graphics for its space-based gameplay. One of the limitations of the original arcade games was that the game was only rendered in a single colour, white. Over 30 years later, [Arcade Jason] decided to see what it would take to build a color Asteroids machine.

The ROM hack also modified the shapes of several in-game objects.

The hack relies on the fact that the original game used a four-bit resistor ladder DAC to draw vectors in different intensity levels. Through some ingeniously simple hardware, this DAC is repurposed to denote different colours instead. It’s laced together with a 74LS08 AND gate chip, along with a handful of resistors and diodes. Three bits are used for red, green, and blue, respectively, with the fourth used as a “white boost” signal to allow the differentiation of colours like red and pink, or dark and light blue. It’s then all wired into an RGB vector monitor for final display. After that, it’s just a matter of a simple ROM hack to set the colors of various on screen objects.

Vector monitors are notoriously hard to film well, but it’s clear that in person the output is rather impressive. Making color versions of old retro games is actually a hobby of [Arcade Jason]’s – we’ve featured his color Vectrex before. Video after the break.

Continue reading “Arcade Asteroids, Now In Colour” →

Changing Color Under Pressure

June 15, 2018 by Brian McEvoy 3 Comments

When you saw the picture for this article, did you think of a peacock’s feather? These fibers are not harvested from birds, and in fact, the colors come from transparent rubber. As with peacock feathers, they come from the way light reflects off layers of differing materials, this is known as optical interference, and it is the same effect seen on oil slicks. The benefit to using transparent rubber is that the final product is flexible and when drawn, the interference shifts. In short, they change color when stretched.

Most of the sensors we see and feature are electromechanical, which has the drawback that we cannot read them without some form of interface. Something like a microcontroller, gauge, or a slew of 555 timers. Reading a single strain gauge on a torque wrench is not too tricky, but simultaneously reading a dozen gauges spread across a more complex machine such as a quadcopter will probably require graphing software to generate a heat map. With this innovation it could now be done with an on-board camera in real-time. Couple that with machine learning and perhaps you could launch Skynet. Or build a better copter.

The current proof-of-concept weaves the fibers into next-generation bandages to give an intuitive sense of how tightly a dressing should be applied. For the average first-aid responder, the rule is being able to slide a finger between the fabric and skin. That’s an easy indicator, but it only works after the fact whereas saying that the dressing should be orange while wrapping gives constant feedback.

Color-Coded Key Opens Doors, Opportunities

March 9, 2018 by Bryan Cockfield 20 Comments

Of all the ways to open up a lock, there are some tried and true methods. Keys, combinations, RFIDs, picks, and explosives have all had their time and place, but now someone else wants to try something new. [Erik] has come up with a lock that opens when it is shown a pattern of colors.

The lock in question uses a set of color coded cards as the “keys”. When the cards are inserted in the lock, a TCS230 color sensor interprets the pattern on the cards and sends the information over to an Arduino Uno. From there, the Arduino can command the physical lock to open if the pattern is a match, although [Erik] is still waiting on the locking mechanism to arrive while he continues to prototype the device.

This is a fairly unique idea with a number of upsides. First, the code can’t be “stolen” from inside a wallet like RFID cards can. (Although if you can take a picture of the card all bets are off.) If you lose your key, you can simply print another one, and the device is able to handle multiple different keys and log the usage of each one. Additionally, no specialized equipment is needed to create the cards, unlike technologies that rely on magnetic strips. Of course, there’s always this classic way of opening doors if you’d rather go old school with your home locks.

Continue reading “Color-Coded Key Opens Doors, Opportunities” →

Sculptural Grade M&M Sorter

February 1, 2018 by Lewin Day 18 Comments

Sorting M&Ms is really only a major concern if you happen to be working on a Van Halen tour, but it’s a fun exercise nonetheless. It’s for this reason we see plenty of sorting projects come our way, varying from the breadboard and cardboard variety, all the way up to final university projects. Today, [Karl] has blessed us with their sculptural-grade offering, and the attention to detail is stunning.

The project has been in gestation in [Karl]’s mind, on and off, for 10 years or so. The big problem centered around reliably separating out one M&M at a time from a hopper of many. From time to time, [Karl] would speak with other builders using similar techniques to his failed experiments, who often reported that the secret to their machine’s reliability was… careful video editing. It was only when a parts sorter flashed across the Hackaday feed that [Karl] found the mechanism that would work to make his project a reality.

Now that the individual candies could readily be separated and fed through a machine, the rest of the project came together quickly. A color sensor was combined with servos and a stepper motor to duct M&Ms into separate flasks.

The real value of this build, however, is in the overall attention paid to the aesthetics of the final product. The device was built to be a kinetic sculpture, able to run reliably with the minimum of attention at the behest of even an untrained user. By carefully optimising the mechanisms inside and building an attractive enclosure, [Karl] has developed something we’d be proud to show off in a living room.

Vectrex, Finally In Color

January 3, 2018 by Lewin Day 18 Comments

The Vectrex is everybody’s favourite vector-based console from the early 1980s. Vector graphics really didn’t catch on in the videogame market, but the Vectrex has, nonetheless held on to a diehard contingent of fans that continue to tinker with the platform to this day. [Arcade Jason] just so happens to be leading the pack right now.

The Vectrex has always been a monochrome machine, capable of only displaying white lines on its vector monitor. Color was provided by plastic overlays that were stuck to the screen, however this was never considered a particularly mindblowing addition to the console. [Jason] decided he could do better, and dug deep into his collection of vector monitors.

With a 36″ color vector monitor to hand, the Vectrex was laid out on the bench, ready for hacking. The bus heading to one of the DACs was hijacked, and fed through a series of OR and AND logic to generate color signals, since the original Vectrex hardware had no way of doing so. This is then fed to the color monitor, with amazing results.

[Jason]’s setup is capable of generating 8 colors on the screen, and it’s almost by some weird coincidence that this really does make the classic Vectrex games pop in a way they never have before. It’s also a testament to a simpler time that it’s possible to hack this console’s video signals on a breadboard; modern hardware runs much too fast to get away with such hijinx.

It’s an epic hack that through experimentation and some serendipity, has turned out some exciting results. [Jason] is now in the process of taking this to the next level, experimenting with adding color intensity control and other features to the mix.

It’s not [Jason]’s first time around these parts, either – we saw his big-screen Vectrex just a month ago!

[Thanks to Morris for the tip!]

Continue reading “Vectrex, Finally In Color” →